The following definitions and abbreviations are herewith defined, at least some of which are referred to within the following description about at least the prior art and/or the present invention.
3GPPThird Generation Partnership ProjectHSDPAHigh-Speed Downlink Packet AccessHSUPAHigh-Speed Uplink Packet AccessGUIGraphical User InterfaceIBSIn Building SiteOSSOperational Support SystemPSCPrimary Scrambling CodeRNCRadio Network ControllerUEUser EquipmentUMTSUniversal Mobile Telecommunications System    Inter site distance: refers to the distance between sites. For a typical deployment scenario in a dense urban area, this distance might be as low as 300 m.    Tier 1 neighbor conflict: refers to the cases where source site and neighboring site have the same PSC allocated.
Tier 2 neighbor conflict: refers to the case where two different neighboring sites of the same source site have the same PSC allocated.
In UMTS wireless telecommunication networks, each UE is assigned a unique code which it then uses to encode its information bearing signal. The Node B knows the code used by the UE so it is able to decode a signal received from the UE and recover the original data. Furthermore, each Node B is assigned a different scrambling code and each data channel is assigned a different channelization code. For the UE to successfully decode a signal from the Node B it must be able to uniquely identify the site (cell) managed by the Node B. Since the total number of scrambling codes for downlink communications is limited to 512, it becomes necessary to assign scrambling codes to the sites in such a way that the UE at a given point does not receive signals from two sites bearing the same scrambling code. A discussion is provided next about some different techniques which are known for allocating the primary scrambling codes to the Node B's sites within a wireless communication network.
In UMTS a total of 512 scrambling codes are available in downlink and they can be divided into 64 code groups. Each code group has eight scrambling codes. These code groups can be characterized as follows:
TABLE 1Macro cellsCodes 8x + 0, 8x + 1, 8x + 2, 8x + 3, 8x + 4, 8x + 5, 8x + 6, where x = 0 to 63Tall Boomer sites +Codes 8x + 7 where x = 0 to 63IBS + New Sites
The tall boomer sites are those which can give significant coverage but also pose bigger risks of being the source of interference to other sites. IBS includes in-building cells.
The above code partitions can be depicted as follows:
TABLE 264 Code GroupsColors Groups1917. . .505Macro Sites21018. . .50631119. . .50741220. . .50851321. . .50961422. . .51071523. . .51181624. . .512Boomer + IBS
FIG. 1A (PRIOR ART) depcits an exemplary guideline for codes with respect to the orientation of the antenna in the Node B's site. In this illustration, there is depecited a Node B's macro site 102 and a Node B's IBS site 104.
In UMTS wireless communication networks, the neighboring sites can be allocated scrambling codes utilizing various strategies. The choice of the allocation scheme has impact on processing requirements and synchronization performance at the UE. For instance, consider the case of a simple network comprising of only six adjacent sites. One way of code planning such a network would be to use different scrambling codes belonging to the same code group or alternatively, different codes could be assigned which are taken from exactly six different code groups. The former technique eventually oversimplifies a second stage of synchronization (frame synchronization and code group determination) and imposes all the required processing on a third stage of synchronization (scrambling code determination). In contrast, the latter technique puts all the processing on the second stage of synchronization (frame synchronization and code group determination) and totally eliminates the third stage of synchronization (scrambling code determination). The first stage of synchronization is slot synchronization. Consequently, the best code planning strategy is a trade-off between the processing load on the UE and the synchronization time or effectively the performance of synchronization procedure.
At least one known scrambling code planning technique in order to simplify the initial planning follows these two conditions:                Treat all sites as 3-sector site.        Every 21 sites will have codes from the same scrambling code set (color group).        
Therefore, the 21 sites from one “color group” will be assigned primary scrambling codes from one of the primary scrambling code sets 1,2, 3, . . .8 where the primary scrambling code set 1 is reserved for IBS, high boomer and new sites. TABLE 1 shows the color groups starting with scrambling code 0, 1 ,2, . . . 7 however for naming them the terms primary scrambling code sets are used hereinafter where the primary scrambling code set 1 (starts with code 0), the primary scrambling code set 2 (starts with code 1), . . . the primary scrambling code set 8 (starts with code 7). TABLES 3A and 3B illustrate this particular scheme for multiple 21 sites:
TABLE 3ASET1Sec-1Sec-2Sec-3SET2Sec-1Sec-2Sec-3SET3Sec-1Sec-2Sec-3SET4Sec-1Sec-2Sec-310816119171210181311192243240225334122634422273543348566434957653505866351596747280884738189474829047583915961041125971051135981061145991071156120128136612112913761221301386123131139714415216071451531617146154162714715516381681761848169177185817017818681711791879192200208919320120991942022109195203211102162242321021722523310218226234102192272351124024825611241249257112422502581124325125912264272280122652732811226627428212267275283132882963041328929730513290298306132912993071431232032814313321329143143223301431532333115336344352153373453531533834635415339347355163603683761636136937716362370378163633713791738439240017385393401173863944021738739540318408416424184094174251841041842618411419427194324404481943344144919434442450194354434512045646447220457465473204584664742045946747521480488496214814894972148249049821483491499
TABLE 3BSET5Sec-1Sec-2Sec-3SET6Sec-1Sec-2Sec-3SET7Sec-1Sec-2Sec-3SET7Sec-1Sec-2Sec-314122015132116142217152322836442293745230384623139473526068353616935462703556371476849247785934788694479879551001081165101109117510211011851031111196124132140612513314161261341426127135143714815616471491571657150158166715115916781721801888173181189817418219081751831919196204212919720521391982062149199207215102202282361022122923710222230238102232312391124425226011245253261112462542621124725526312268276284122692772851227027828612271279287132923003081329330130913294302310132953033111431632433214317325333143183263341431932733515340348356153413493571534235035815343351359163643723801636537338116366374382163673753831738839640417389397405173903984061739139940718412420428184134214291841442243018415423431194364444521943744545319438446454194394474552046046847620461469477204624704782046347147921484492500214854935012148649450221487495503Note:Codes 504 to 511 can be used in IBSs or any 4th sectors, and they can be used as an extra scrambling code in each primary scrambling code set 1, 2 . . . 7.
In view of TABLES 3A-3B, the first site will have codes (1, 9, 17), the second site will have codes (25, 33, 41), etc. Plus, sites in the neighboring “color group” will have SET 1 or SET2 or SET3 of scrambling codes as compared to the first group. As such, sites of the neighboring “color group” will start from (1, 9, 17) etc. For the IBS, new sites and tall boomer sites, the first site may start from (0, 8, and 15). However, it should be noted that in these tables there are no macro-sites and micro-sites in the neighbors that have the same code group. FIG. 1B (PRIOR ART) is provided to graphically illustrate the aforementioned concepts.
Most of the existing scrambling code planning techniques utilize some sort of coverage prediction to allocate the primary scrambling codes to the sites in the wireless communication is network. However, the existing scrambling code planning techniques do not consider the site density (or inter-site distance) or neighbor tier information while planning the scrambling codes which may result in a tier 1 and tier 2 neighbor conflict in dense urban areas where site density is very high. In fact, some of the existing scrambling code planning techniques fail to even consider scrambling code grouping in one cluster to maintain higher order orthogonality. Accordingly, there is and has been a need to address these shortcomings and other shortcomings of the existing code planning techniques. This need and other needs are addressed by the present invention.